It is known that there are many areas of the earth, usually subtropical and tropical regions, in which living conditions for Europeans and others accustomed to temperate climatic conditions and the indigenous population may involve considerable discomfort and even unhealthy ambient weather environments because of high daytime or nightime temperatures and high relative humidity. Typical of such hot and damp climates are those which prevail in the Persian Gulf regions, for example, in Bahrein, in which summertime average temperatures may be 32.degree. C., the sea water temperature can be 31.degree. C. and the relative humidity of the ambient air can be 70%.
Living conditions in such regions, especially in cities and towns in which the street temperature is still higher because of radiation of heat from the walls of the buildings flanking the street, can be difficult because of the heat and humidity. The problem is intensified by the fact that internal living conditions frequently require central or room air conditioning and in most cases the heat abstracted from the building interiors is discharged into the street as well. The air conditioners used in such cases are usually powered by electricity and most of the electrical energy employed ultimately is transformed into heat which is introduced into the environment surrounding the buildings in such towns.
A further problem in such regions is often the availability of a suitable source of potable or drinkable water. In such locations, the ground water level is customarily very low and evaporation of water occurs at a high rate. Thus one must use very deep wells where subsurface water is available, or produce drinkable water by complex energy-consuming processes such as salt water desalination. The latter expedients are only applicable in coastal regions and more inland areas thus must be supplied with water by expensive transport systems, e.g., subsurface pipelines.